<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Test Nested Iframes</title>
</head>
<body>
    <h1 id="main-heading">Main Page with Nested Iframes</h1>
    
    <div id="main-content">
        <p id="main-paragraph">Main page content</p>
        <button id="main-button">Main Button</button>
    </div>
    
    <iframe id="parent-iframe" src="test_iframe_parent_level.html" style="width: 100%; height: 800px;"></iframe>
    
    <div id="after-iframe">
        <p>Content after parent iframe</p>
    </div>
</body>
</html>

